alright well i want to get my teeth whitened but dont know which to pick... britesmile or zoom.. britesmile says it usually whitens up to 9 shades and zoom says 8 shades.. however where i live i found a dentist who will do zoom for me for $450 plus include take home trays for touch ups... only problem is zoom has no guarantee but extreme makeover uses it so it must be good.. the other place that offers zoom here is $700 and britesmile is $600.. any thoughts would be good thanks!